Ebay or dealership

https://m.ebay.com/itm/MITSUBISHI-OE...wAAOSwjvJZRDtc

The axle goes all the way through the threaded nut and the outer part of the nut must be hammered into the keyway to prevent it from backing out. If they made the hammered area non threaded it could be easily reused. Maybe someone can hunt junkyards for one that is reusable.

Attachment 6656